|Stamp Name||Air 9 Revenue Stamp Converted into Air Mail Unit Postage Stamp (1949)|
|Stamp Cat Standard||Air Mail Stamps|
|Dimension of stamps(mm.)|
|Size of souvenir Sheet (mm.)|
|Perforation||12 1/2 - 14|
The original revenue stamp inscription at the top and bottom of the stamps is deleted along with the floral decorations, and the necessary postal wording 〝中華民國郵政國內航空費〞(Postal Administration of the Republic of China; domestic air mail postage) is overprinted in two horizontal lines in the middle by metal plates by the Nanking Printing Press, Canton(廣州南京印務局).